/* Signer.java --- Signer Class
   Copyright (C) 1999 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

As a special exception, if you link this library with other files to
produce an executable, this library does not by itself cause the
resulting executable to be covered by the GNU General Public License.
This exception does not however invalidate any other reasons why the
executable file might be covered by the GNU General Public License. */

package java.security;

/**
   Signer is a subclass used to store a digital signature key with 
   an Identity.

   @author Mark Benvenuto <ivymccough@worldnet.att.net>

   @since JDK 1.1
 */
public abstract class Signer extends Identity
{
  private PrivateKey privateKey = null;

  /**
     Constructs a new Signer.
   */
  protected Signer()
  {
  }

  /**
     Constructs a new Signer with the specified name.

     @param name the name of the identity.
   */
  public Signer(String name)
  {
    super(name);
  }

  /**
     Constructs a new Signer with the specifid name and 
     IdentityScope.

     @param name the name of the identity.
     @scope the IdentityScope to use

     @throws KeyManagementException if duplicate identity name 
     within scope
   */
  public Signer(String name, IdentityScope scope)
    throws KeyManagementException
  {
    super(name, scope);
  }

  /**
     Returns the private key for this signer.

     This class checks the security manager with the call 
     checkSecurityAccess with "getSignerPrivateKey".

     @returns the private key for the signer

     @throws SecurityException - if the security manager denies 
     access to "getSignerPrivateKey"
   */
  public PrivateKey getPrivateKey()
  {
    SecurityManager sm = System.getSecurityManager();
    if (sm != null)
      sm.checkSecurityAccess("getSignerPrivateKey");

    return privateKey;
  }

  /**
     Specifies the KeyPair associated with this Signer.

     This class checks the security manager with the call 
     checkSecurityAccess with "setSignerKeyPair".

     @param pair the keyPair

     @throws InvalidParameterException invalidly intialized key pair
     @throws KeyException another key error
     @throws SecurityException - if the security manager denies 
     access to "getSignerPrivateKey"
   */
  public final void setKeyPair(KeyPair pair)
    throws InvalidParameterException, KeyException
  {
    SecurityManager sm = System.getSecurityManager();
    if (sm != null)
      sm.checkSecurityAccess("setSignerKeyPair");

    try
      {
	if (pair.getPublic() != null)
	  setPublicKey(pair.getPublic());
	else
	  throw new InvalidParameterException();

      }
    catch (KeyManagementException kme)
      {
	throw new KeyException();
      }

    if (pair.getPrivate() != null)
        privateKey = pair.getPrivate();
    else
      throw new InvalidParameterException();
  }

  /**
     Returns a string representing this Signer.

     @returns a string representing this Signer.
   */
  public String toString()
  {
    return (getName() + ": " + privateKey);
  }
}